Tag Archives: Tail docking

Tail amputation causes acute and sustained changes in peripheral somatosensory nerve function involving inflammatory and neuropathic pain pathways

Oral presentation

 Recent Advances in Animal Welfare Science (VI),

UFAW Animal Welfare Conference, Centre for Life, Newcastle, UK 28th June 2018

Coexpression analysis of dorsal root ganglia from tail amputated pigs at different ages reveals long-term transcriptional signatures associated with wound healing and inflammation, and neuropathic pain pathways

DA Sandercock1, JE Coe1, MW Barnett2, TC Freeman2, P Di Giminiani3 and SA Edwards3

1 Animal and Veterinary Science Research Group, SRUC, Edinburgh UK,

2 The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh UK

3 School of Agriculture, Food and Rural Development, Newcastle University, Newcastle-upon-Tyne, UK

 Concerns exist that docking and biting injuries may be a cause of long term pain in the remaining tail stump during the pig’s lifetime. The potential for long-term pain has been linked to sustained cellular and molecular changes in peripheral sensory neuronal activity. The aim of this study was to conduct a transcriptome analysis of caudal dorsal root ganglia (DRG) gene expression profiles from pigs subjected to tail amputation, in particular examining genes known to be associated with inflammation and neuropathic pain. Microarray analysis was performed on caudal DRG from sham (control) and tail amputated pigs 1, 8 and 16 weeks after tail treatment at either 3 days (neonate) or 63 days (juvenile). Tail amputation injury induced highly significant gene expression changes (both up and down) compared to sham-treated intact controls at both ages (518-2,794 genes, FDR < 0.05) that were still evident 16 weeks after tail amputation. Network correlation analysis using the Markov clustering (MCL) algorithm to define expression modules revealed two highly correlated (PCT r2 = ≥0.75), interrelated transcript expression clusters related to (A) neuronal function (759 genes) and (B) wound healing (273 genes). In cluster A, gene ontology (GO) and pathway enrichment analysis identified genes with significant GO terms for voltage- and ligand-gated ion channel activity linked to regulation of membrane potentials, neurotransmitter levels and synaptic signalling. In cluster B significant gene expression was associated with receptor binding, protein transcription activity and regulation, linked to processes such as response to wounding, regulation of response to wounding, inflammatory response and activation of immune response. Cross-reference against an integrated database of known genes involved in the regulation of inflammatory and neuropathic pain revealed 124 and 61 pain–associated genes in clusters A and B, respectively. Key functional families of ion channels and receptors were significantly down-regulated in cluster A, in particular voltage-gated potassium channels and GABA receptors which are linked to increased neuronal excitability. Up-regulated functional gene families in cluster B were mostly linked to inflammation, macrophage activity, neurohormone and opioid peptide activity. DRG gene expression profiles appear to be linked to sustained tissue inflammation and remodelling (ca. 4 months) and pain perception modulation consistent with adaptive, compensatory responses to injury induced increases in peripheral sensory neuron excitability in the injured tail stump. Tail amputation causes acute and sustained changes in peripheral somatosensory nerve function involving inflammatory and neuropathic pain pathways which have implications for pig welfare.


A review of tail docking in farm animals

The long and short of it: A review of tail docking in farm animals
Mhairi A. Sutherland, Cassandra B. Tucker, 2011. Applied Animal Behaviour Science 135: 179-191


Tail docking involves amputating a portion of the tail for a variety of reasons. We review the scientific evidence for the rationale for tail docking, a description of the different methods used, the pain response to the procedure and the effectiveness of pain alleviation, and, finally, the alternatives to tail docking and policy regarding the practice. We focus on the three main agricultural species that are tail docked as a management practice: pigs, sheep, and dairy cattle. Methods of tail docking include cutting with a knife or scalpel, cutting with a hot docking iron, or application of a constrictive rubber ring. All methods are commonly performed without analgesia or anaesthesia, and all likely result in some degree of pain. As with any procedure that alters the integrity of an animal, it is important to consider the rationale behind docking in order to evaluate if it is necessary. Tail docking in pigs is routinely conducted on commercial swine farms because it can reduce the incidence of tail biting, an injurious and undesirable behaviour. Both behavioural and physiological changes indicate that tail docking is painful in pigs, but until robust and consistent methods for preventing tail biting are identified, this procedure is likely to continue as a management practice. This approach is reflected in public policy about the procedure. There is both behavioural and physiological evidence that tail docking is painful for sheep; both responses are reduced when pain relief is provided. Prevention of fly strike is the primary reason given for tail docking sheep, but the scientific evidence to support this rationale is surprisingly sparse. Further research is required to justify tail docking of sheep as a routine practice. Dairy cattle are docked because this practice is thought to improve cow cleanliness and udder health, however, there is no scientific evidence supporting this rationale. Tail docking cattle results in relatively few behavioural or physiological indicators of pain, but docked cows are unable to effectively remove flies from their hind end. The practice of tail docking dairy cattle is banned, discouraged or declining in most industrialized countries except the US. The long-term pain associated with tail docking is not well understood in pigs, sheep or cattle. In cases where tail docking may be justified by demonstrated benefits for the animal (possibly in case of pigs and sheep), further research is needed to find either practical alternatives or ways to alleviate the pain associated with this procedure.

Curly pig tail farming in Finland and Italy (two EC videos)

EU legislation on the welfare of pigs (Council Directive 2008/120/EC laying down minimum standards for the protection of pigs) does not allow routine tail-docking and requires farmers to provide to their pigs “manipulable material” such as straw, hay or sawdust.
To better inform farmers how to prevent routine tail docking, the Commission developed educational materials. The two videos present success stories in achieving the goal of rearing not-tailed pigs.

A Finnish farming with an intensive system rearing piglets with intact, curly tails.

An Italian farmer proud of rearing curly tails on straw

Characterization of short- and long-term mechanical sensitisation following tail docking in pigs

Characterization of short- and long-term mechanical sensitisation following surgical tail amputation in pigs. By Pierpaolo Di Giminiani, Sandra A. Edwards, Emma M. Malcolm, Matthew C. Leach, Mette S. Herskin & Dale A. Sandercock. 2017. Nature Scientific Reports.

Commercial pigs are frequently exposed to tail mutilations in the form of preventive husbandry procedures (tail docking) or as a result of abnormal behaviour (tail biting). Although tissue and nerve injuries are well-described causes of pain hypersensitivity in humans and in rodent animal models, there is no information on the changes in local pain sensitivity induced by tail injuries in pigs. To determine the temporal profile of sensitisation, pigs were exposed to surgical tail resections and mechanical nociceptive thresholds (MNT) were measured in the acute (one week post-operatively) and in the long-term (either eight or sixteen weeks post-surgery) phase of recovery. The influence of the degree of amputation on MNTs was also evaluated by comparing three different tail-resection treatments (intact, ‘short tail’, ‘long tail’). A significant reduction in MNTs one week following surgery suggests the occurrence of acute sensitisation. Long-term hypersensitivity was also observed in tail-resected pigs at either two or four months following surgery. Tail amputation in pigs appears to evoke acute and sustained changes in peripheral mechanical sensitivity, which resemble features of neuropathic pain reported in humans and other species and provides new information on implications for the welfare of animals subjected to this type of injury.

See also our article in PigProgreess.

Pigs in pain

Herskin, M.S. and P. Di Giminiani, 2017.  Pigs in pain—causes, mechanisms, and possibilities for future development. Abstract from BEHAVIOR, HOUSING, AND WELL-BEING SYMPOSIUM: FINDING EFFECTIVE WAYS TO MANAGE PAIN IN LIVESTOCK, a conference of the  American Society for Animal Science Midwestern Meeting, Omaha, NE, 13-15 March 2017


Despite a long history of debate about negative affective states in animals, it was only in the last decades of the 20th century that the state of pain was mentioned in definitions of animal welfare, included in veterinary education, and became a target of scientific interest. Pain is a perceptional phenomenon built from information gathered by specialized sensory receptors for tissue damage and integrated into a discrete experience with a negative emotional valence in the brain. Based on knowledge about porcine neuroanatomy, physiology, and studies focusing on pig behavior and pathology, we review evidence for causes of pain in pigs, underlying biological mechanisms, as well as the possibility to quantify different types of indicators of pain states relevant to the welfare of the animals under production conditions. The presentation will primarily focus on pigs because of the dual purpose of this species as a meat producing as well as research animal species (the latter driven by the anatomical and physiological homologies with humans), making pigs unique among livestock. We will present methodologies and results from current research projects across Europe and North America targeting typical industry-related injuries (e.g., tail docking, lameness, and shoulder lesions) and aiming to understand the welfare consequences for the pigs. Throughout the talk, the emphasis will be put on future opportunities to link research outcomes with industry initiatives toward the improvement of animal welfare and production. In addition, possible future research efforts to help face current methodological limitations and favor a more comprehensive evaluation of animal pain as an overall experience will be discussed. This seeks to facilitate common future targeted research and enable us to overcome the paradoxical low level of knowledge about porcine pain and its alleviation under production conditions.

Tooth treatment

Effect of tail docking on welfare and performance of pigs

Effect of tail docking on welfare and performance of pigs during nursery and growing-finishing periods
By Y. Li and L. J. Johnston. 2017. J. Anim. Sci. 95:34 (conference abstract)


Tail docking of pigs is under scrutiny due to concerns about animal welfare. To reevaluate the consequences of raising pigs without tail docking under modern, commercial-like conditions, a study was conducted to compare welfare, behavior, and performance of pigs with and without tail docking. Pigs farrowed to 37 sows were used with half of each litter tail-docked (docked) after birth and remaining pigs left with tails intact (intact). During the nursery period, pigs (n = 336, initial wt = 7.8 ± 1.5 kg) were housed in 20 docked pens and 22 intact pens (8 pigs/pen). During the growing-finishing period, pigs (n = 240, initial wt = 24.9 ± 2.9 kg) were housed in 8 pens (4 pens each of docked and intact, 30 pigs/pen) for 16 wk (avg final wt = 126.2 ± 10.3 kg). Weight gain and feed intake were recorded. All pigs were assessed for tail damage and skin lesions every 4 wk and during outbreaks of tail biting. Behaviors were video-recorded twice weekly for 13 wk during the growing-finishing period. Carcass weights and incidence of carcass trim loss were recorded. More intact pigs experienced tail damage during both nursery (41% vs. 2%; chi-square = 75.7; P < 0.0001) and growing-finishing (89% vs. 48%; chi-square = 76.2; P < 0.0001) periods than docked pigs. Intact pigs spent more time tail biting (0.31% vs. 0.06%; P < 0.001) and tended to spend less time drinking (1.58 vs. 1.77%; P < 0.10) compared to docked pigs. Intact pigs experienced the first outbreak of tail biting at 11 wk of age, which occurred 6 wk earlier compared to docked pigs. Furthermore, 21% of intact pigs vs. 5% (P < 0.001) of docked pigs were removed due to tail damage. Tail docking did not affect ADG (nursery: 0.48 vs. 0.49 kg, SE = 0.04; growing-finishing: 0.86 vs. 0.87 kg, SE = 0.01 for docked and intact pigs, respectively) or skin lesions of pigs. For pigs that were not removed, ADFI was not different between pens with docked pigs and pens with intact pigs. As a consequence of carcass trim loss, carcass contamination, and mortality, 90% of intact pigs vs. 97% of docked pigs were harvested for full value. These data suggest that raising pigs without tail docking in a confinement housing system increases incidence of tail biting and tail damage, resulting in higher morbidity, reduced value, and compromised welfare of pigs.

Tail docking using hot iron cautery

Report good practices for rearing pigs with intact tails

Report identifies good practices for rearing pigs with intact tails

DG Health and Food Safety – European Commission
A new report provides evidence that there are solutions to counter the commonly held belief that rearing pigs and avoiding tail docking is impossible.

Based on visits to three countries where tail docking is not performed routinely, it summarises good practices to rear pigs with intact tails. It finds that the key to do so is to lower stress levels through active management of enrichment materials; feed and air quality; reduction of competition between animals; and good animal health status. Another key factor to ensure intact tails is that farmers rapidly identify tail biters and remove them to prevent the escalation of tail biting.

The report can be found here…

Just a nice picture of what a pig’s tail should look like

What do you see?

Please have a look at this pig’s tail. You may note that contrary to most EU pigs, this Finnish pig has a curly tail. In addition, please note that this pig does not only has a curly tail. Its tail also has a hairy plume. That is what a pig’s tail should look like: It is the pig’s welfare thermometer.

Curly tail as sign of melting pig-welfare iceberg

The FareWellDock project has accumulated scientific information directed at reducing the need for tail docking in Europe. In this way it has contributed to ending the progressive melting of the pig-welfare iceberg. But sometimes, a picture says more than a thousand words, for the pig’s tail is an iceberg indicator for pig welfare.

Culty pig tail with brush

Curly pig tail (© Mari Heinonen).

Survey on straw use and tail biting on Swedish pig farms

Wallgren, T. R. Westin and S. Gunnarsson, 2016.  A survey of straw use and tail biting in Swedish pig farms rearing undocked pigs. Acta Veterinaria Scandinavica 58:84.


Background: Tail biting is a common problem in intensive pig farming, affecting both welfare and production. Although routine tail docking is banned within the EU, it remains a common practice to prevent tail biting. Straw as environmental enrichment has been proposed as an alternative to tail docking, but its effectiveness against tail biting and function in manure handling systems have to be considered. The aim of the study was to survey how pigs with intact tails are raised and how tail biting is handled in Sweden, where tail docking is banned through national legislation. The study emphasises straw usage and its association with tail biting pigs and problems in the manure handling system. The expectation is that this information could be conveyed to the rest of the EU to reduce the need for tail docking.

Results: In a telephone survey of randomly selected Swedish pig farmers (46 nursery and 43 finishing pig units) with at least 50 sows or 300 finishing places, it was found that straw was used by 98% of the farmers. The median daily straw ration provided was 29 g/pig for nursery and 50 g/pig for finishing pigs in systems with partly slatted flooring. The reported prevalence of tail biting was 1.6% at slaughter. The majority of farmers reported that they never had manure handling problems caused by straw (56% of nursery units and 81% of finishing pig units). A proportion of farmers (37%) also provided with additional material apart from straw on some occasions, which may have affected tail biting prevalence and manure handling problems.

Conclusions: Swedish farmers rear undocked pigs without large problems with tail biting. Straw is the main manipulable material used, and additional manipulable material is used to various extents. The low incidence of straw obstructing the manure handling systems implies that it is indeed possible to use straw in partly slatted flooring systems, reducing the need for tail docking. The impact of using additional manipulable material is unknown and requires more investigation to separate the impact of such material from the impact of straw.